Eco-friendly nano colloids for enhanced black gram (Vigna mungo) seed viability: experimental and computational analysis

An experiment was designed to fabricate Polyvinylpyrrolidone-coated zein-zipped herbal molecules infused nano colloids (PZCA-NCs) for extending Vigna mungo seeds storability. PZCA-NCs was synthesized and characterized in Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction (XRD), Particle size analyser, Zeta Potential, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-dispersive X-ray spectroscopy (EDAX). The bio-efficacy of PZCA-NCs on seed storability was tested under accelerated ageing. The sphere-shaped PZCA-NCs possess a 151 nm size with 44.5mV zeta potential at an encapsulation of 73.44% curcumin and 69.0% azadirachtin. The spectra of FTIR, UV -Vis, XRD, and TGA confirmed the functionality, composition, and stability of PZCA-NCs. The dialysis diffusion method was utilised to study the maximum cumulative release of biomolecules 6.1ppm (88.4%) azadirachtin and 64.57ppm (88.2%) curcumin at pH 7.4. Density functional theory (DFT) was used to determine the binding mode of molecules and examine ligand interactions in PZCA-NCs. PZCA-NCs treated seeds at 25 mL/kg enumerated higher germination, vigour index, alpha-amylase, dehydrogenase, and catalase and peroxidase activity under ageing. Seeds storage pathogen infection was reduced with an increase in the concentration of PZCA-NCs coating. The bioassay results on insect activity evidenced that PZCA-NCs at 15.76 mL/kg killed 50% and 40 mL/kg killed 100% of the storage insect Callosobruchus maculatus. Toxicity study on Macrophomina phaseolina showed that PZCA-NCs at 35 mL resulted in 0.8 cm mycelia growth with 91.11% inhibition zone, while at 45 mL had zero growth of fungal mycelia with 100% inhibition. The study concludes that PZCA-NCs act as an efficient seed invigoration material to extend the vitality of Vigna mungo seeds during ageing.